It's a no to childminding in my LA too - foster children are very different to children from (presumably) stable homes that you're childminding. They can be very anti-social and struggle with other children. They can be violent. Particularly in the first few months of a placement they need 100% of your attention to form an attachment to you. Plus you can be out of the house a significant proportion of each day with meetings/contact/appointments. These are all confidential and taking an unrelated child along would be frowned upon, if not vetoed outright.

This might all be different where you live though, and also if you're thinking of fostering older children. I'd give your local council a ring.

I've known a childminder foster and why she was able to provide to the child was amazing in relation to stimulation and socialising however there were concerns that as a young child who had been through a lot she may have benefitted from more 1:1 time

Hi- I am a childminder(15 yrs) and I also foster (12 yrs). I only childmind part time as it is difficult to fit in meetings, contact and picking up foster child from school (who has to be prioritised). I think it would be difficult to balance both if you are new to both roles.